1. Field of the Invention
The present invention relates to a computer system, a device sharing method, and a device sharing program. The invention relates more particularly to PCI device sharing in which a plurality of virtual computers formed on a plurality of physical computers share a PCI SR-IOV (Single Root I/O Virtualization) device, which requires an interface between a PF (Physical Function) and a VF (Virtual Function).
2. Description of the Related Art
A virtual computer system in which a plurality of virtual computers (LPARs) are built on a physical computer to share an I/O device is put into practical use for the purpose of using a computer system more intensively, with increased power savings, at a lower cost, and with enhanced efficiency.
As an associated conventional technique, an I/O device virtual sharing method disclosed, for instance, in JP-A-2004-252591 enables a plurality of virtual computers built on a single physical computer to share a PCI I/O device.
Further, a PCI-SIG standard is disclosed in Single Root I/O Virtualization and Sharing Specification Revision 1.0(Sep. 11, 2007) Chapter 1 Architectural Overview (page 11 to page 24). According to this standard, device sharing can be achieved when a plurality of VFs formed in an SR-IOV-compliant device are allocated to a plurality of virtual computers on an SR-IOV-compliant VMM (Virtual Machine Monitor).
Furthermore, a standard that is being developed by the PCI-SIG is disclosed in Multi-Root I/O Virtualization and Sharing Specification Revision 1.0 (May 12, 2008) Chapter 1 Architectural Overview (page 15 to page 34). According to this standard, device sharing can be achieved when a PF and a VF that are formed in an MR-IOV (Multi-Root IOV) compliant device are allocated to a plurality of physical computers on an MR-IOV-compliant computer system.